JP2021120556A - Evaporated fuel treatment device - Google Patents

Abstract

To provide an evaporated fuel treatment device capable of accurately learning a valve opening start position of a sealing valve and more appropriately and quantitatively controlling an opening of the sealing valve.SOLUTION: In a control device 5 for an evaporated fuel treatment device 1, an opening command section 51 transmits an opening command amount K1 for determining an opening of a sealing valve 3 to an actuator 35. When the opening command amount K1 is gradually increased from zero in a learning operation 504, a valve opening start learning section 52 learns a valve opening start amount K0 on the basis of the opening command amount K1 when pressure P of gas-phase gas starts to lower. A valve opening threshold value setting section 53 sets a valve opening threshold value TH for determining that the pressure P of the gas-phase gas started to lower, on the basis of pre-learning pressure P0 that is the pressure P of the gas-phase gas prior to a time when the learning operation 504 is started.SELECTED DRAWING: Figure 2

Description

The present invention relates to an evaporative fuel treatment device provided in a vehicle.

In a vehicle having an internal combustion engine, the liquid fuel used for the internal combustion engine is stored in a fuel tank. In the gas phase in the fuel tank, pressure is generated by the vapor pressure of the evaporated fuel or the like according to the temperature. When refueling the fuel tank, an evaporative fuel treatment device having a canister capable of adsorbing the evaporative fuel is used so as not to release the evaporative fuel constituting the gas phase to the outside.

Then, before starting refueling to the fuel tank, the airtight valve provided in the vapor pipe connecting the fuel tank and the canister is opened, and the evaporated fuel in the fuel tank is adsorbed on the adsorbent of the canister. The fuel component adsorbed on the adsorbent of the canister is supplied to the intake pipe of the internal combustion engine and used when the internal combustion engine is burned. In addition, the evaporated fuel in the fuel tank may be supplied to the intake pipe of the internal combustion engine by bypassing the canister.

The closed valve used in the evaporative fuel treatment device normally closes the vapor pipe connecting the fuel tank and the canister. On the other hand, when there is a signal from the control device to the actuator of the closed valve, the vapor closed pipe is opened by the closed valve. In the opening / closing operation of the vapor pipe by the closed valve, there are cases where the opening degree is not adjusted, the opening degree is adjusted in about two steps, the opening degree is quantitatively adjusted, and the like.

As an evaporative fuel treatment device that quantitatively adjusts the opening degree of the closed valve using a stepping motor, for example, there is one described in Patent Document 1. In this evaporated fuel treatment device, the flow rate of gas flowing from the fuel tank to the purge pipe connected to the canister can be adjusted by changing the stroke amount of the sealing valve as the sealing valve when the fuel tank is depressurized. Further, the sealing valve in this evaporated fuel processing device can learn the valve opening start position based on the stroke amount of the valve movable portion with respect to the valve seat in the valve opening direction when the internal pressure of the fuel tank drops by a predetermined value or more. It is configured as follows.

JP 2015-102019

In Patent Document 1, the predetermined value, which is a threshold value for learning the valve opening start position of the closing valve, takes into consideration, for example, variation in the characteristics of the sensor that detects the internal pressure of the fuel tank and liquid level fluctuation due to vehicle running or the like. It is set. However, since gasoline, which is a fuel, is volatile, the internal pressure of the fuel tank is likely to change due to changes in the environment such as the ambient temperature and the remaining amount of fuel even when the vehicle is stopped, resulting in pressure pulsation. May cause a large variation in the value detected by the sensor.

In such a case, if the valve opening start position is not properly learned, the opening degree of the closed valve based on the valve opening start position cannot be accurately controlled. In order to prevent erroneous learning, the threshold value for judgment should be a size that takes into account the pressure pulsation due to environmental factors, but on the other hand, if the threshold value is large, the valve opening start position is set in an environment where the pressure pulsation is small. It takes time to detect, and the deviation from the actual valve opening start position becomes large, which may reduce the learning accuracy.

The present invention has been made in view of the above problems, and an evaporative fuel treatment apparatus capable of accurately learning the valve opening start position of a closed valve and controlling the opening of the closed valve more appropriately and quantitatively. It is what we are trying to provide.

One aspect of the present invention is
An evaporative fuel processing apparatus (1) provided in a vehicle (6) having an internal combustion engine (61) and a fuel tank (62) to process the evaporated fuel (F1) in which the fuel in the fuel tank has evaporated.
A canister (2) having an adsorbent (22) for adsorbing the evaporated fuel,
A closed valve (3) provided in the vapor pipe (41) connected from the fuel tank to the canister, and the opening degree of opening and closing the vapor pipe can be quantitatively adjusted by an actuator (35).
A pressure sensor (44) provided in the fuel tank to detect the pressure (P) of the gas phase gas in the fuel tank, and
A purge valve (43) provided in a purge pipe (42) connected from the canister to the intake pipe (611) of the internal combustion engine to open and close the purge pipe.
A sealing operation of closing the vapor pipe by the sealing valve to seal the fuel tank, and a vapor operation of opening the vapor pipe by the sealing valve and purging the vapor phase gas in the fuel tank to the canister (501). A canister purge operation (502) in which the purge pipe is opened by the purge valve to purge the fuel component in the canister to the intake pipe, the vapor pipe is opened by the closed valve, and the purge pipe is opened by the purge valve. A purge operation (503) that opens and purges the gas phase gas in the fuel tank to the intake pipe by bypassing the canister, and an opening degree of the closed valve in at least one of the vapor operation and the purge operation. The control device (5) capable of executing each of the learning operations (504) is provided.
The control device is
An opening command unit (51) for transmitting an opening command amount (K1) for determining the opening of the closed valve to the actuator, and an opening command unit (51).
In the learning operation, when the opening command amount is gradually increased from zero, the valve opening start amount (K0) is based on the opening command amount when the pressure of the gas phase gas starts to decrease. With the valve opening start learning unit (52) to learn
The valve opening threshold (TH) for determining that the pressure of the gas phase gas has started to decrease is based on the pre-learning pressure (P0) which is the pressure of the gas phase gas before the time when the learning operation is started. It has a valve opening threshold value setting unit (53) and a valve opening threshold value setting unit (53).
When the closed valve is opened to perform the vapor operation or the purge operation, the opening command amount by the opening command unit is determined based on the valve opening start amount by the valve opening start learning unit, evaporation. Located in the fuel processing equipment.

The control device of the evaporative fuel treatment device of the above aspect does not set the valve opening threshold value for learning the valve opening start amount of the closed valve to a fixed value, but responds to the pressure of the gas phase gas before the time when the learning operation is started. It is a variable value. The gas phase gas in the fuel tank causes a pulsation in which the pressure changes due to the influence of environmental factors such as the high and low ambient temperature and the amount of fuel remaining. It has been found that the magnitude of the pressure pulsation increases as the pressure of the gas phase gas increases, and the appropriate valve opening threshold considering the pressure pulsation from the tank internal pressure before learning when the closed valve is closed. Can be set. Then, when the gas phase gas pressure is high, the valve opening threshold is increased to prevent erroneous determination during learning, and when the gas phase gas pressure is low, the valve opening threshold is decreased to reduce the valve opening threshold during learning. The determination can be made quickly and accurately. Further, the opening degree of the closed valve can be accurately controlled by performing the vapor operation and the purge operation by the control device using the valve opening start amount of the closed valve obtained by learning.

According to the evaporative fuel processing apparatus of the above aspect, there is provided an evaporative fuel processing apparatus capable of accurately learning the valve opening start position of the closed valve and controlling the opening degree of the closed valve more appropriately and quantitatively. be able to.
The reference numerals in parentheses of each component shown in each aspect of the present invention indicate the correspondence with the reference numerals in the drawings in the embodiment, but the respective components are not limited to the contents of the embodiment.

FIG. 1 is an explanatory view showing a part of a vehicle in which an evaporative fuel treatment device is arranged according to the first embodiment. FIG. 2 is an explanatory diagram schematically showing a control device for the evaporative fuel treatment device according to the first embodiment. FIG. 3 is an explanatory view showing a closed valve in a closed position in the evaporated fuel treatment apparatus according to the first embodiment. FIG. 4 is an explanatory view showing a closed valve at an opening position in the evaporative fuel processing apparatus according to the first embodiment. FIG. 5 is a graph showing the relationship between the opening command amount by the control device and the opening degree of the closed valve according to the first embodiment. FIG. 6 is a graph showing a relationship map between the pressure of the gas phase gas and the valve opening start amount according to the first embodiment. FIG. 7 shows the relationship between the opening degree of the closed valve and the valve opening start amount when the valve opening threshold value by the control device according to the first embodiment is set to a constant value regardless of the pressure region of the gas phase gas for comparison. It is a graph which shows. FIG. 8 is a graph showing the relationship between the opening degree of the closed valve and the valve opening start amount when the valve opening threshold value by the control device is set to a variable value according to the pressure region of the gas phase gas according to the first embodiment. be. FIG. 9 is a graph showing a threshold map showing the relationship between the pressure of the gas phase gas and the valve opening threshold according to the first embodiment. FIG. 10 is a graph showing the relationship between the opening command amount by the control device and the opening degree of the closed valve according to the first embodiment. FIG. 11 is a flowchart showing the learning operation according to the first embodiment. FIG. 12 is a flowchart showing the learning operation according to the first embodiment. FIG. 13 is a flowchart showing the vapor operation according to the first embodiment. FIG. 14 is a flowchart showing the canister purge operation according to the first embodiment. FIG. 15 is a flowchart showing a purge operation according to the first embodiment.

A preferred embodiment of the above-mentioned evaporated fuel treatment apparatus will be described with reference to the drawings.
<Embodiment 1>
As shown in FIG. 1, the evaporated fuel processing apparatus 1 of the present embodiment is provided and used in a vehicle 6 having an internal combustion engine 61 and a fuel tank 62, and processes the evaporated fuel F1 in which the fuel F in the fuel tank 62 has evaporated. Is what you do. The evaporative fuel processing device 1 includes a canister 2, a vapor pipe 41, a closed valve 3, a pressure sensor 44, a purge pipe 42, a purge valve 43, and a control device 5.

The canister 2 has an adsorbent 22 that adsorbs the evaporated fuel F1. The vapor pipe 41 connects the fuel tank 62 to the canister 2. The sealing valve 3 is provided in the vapor pipe 41, and the opening degree of opening and closing the vapor pipe 41 can be quantitatively adjusted by the stepping motor 35 as an actuator. The pressure sensor 44 is provided in the fuel tank 62 and detects the pressure P of the gas phase gas G in the fuel tank 62. The purge pipe 42 connects the canister 2 to the intake pipe 611 of the internal combustion engine 61. The purge valve 43 is provided in the purge pipe 42 and opens and closes the purge pipe 42.

As shown in FIG. 2, the control device 5 can execute each of the sealing operation, the vapor operation 501, the canister purge operation 502, the purge operation 503, and the learning operation 504.
The sealing operation is an operation in which the vapor pipe 41 is closed by the sealing valve 3 to seal the fuel tank 62.
The vapor operation 501 is an operation of opening the vapor pipe 41 by the sealing valve 3 and purging the gas phase gas G in the fuel tank 62 to the canister 2.
The canister purge operation 502 is an operation of opening the purge pipe 42 by the purge valve 43 and purging the fuel component in the canister 2 to the intake pipe 611.
The purge operation 503 is an operation in which the vapor pipe 41 is opened by the closed valve 3 and the purge pipe 42 is opened by the purge valve 43, bypassing the canister 2 and purging the gas phase gas G in the fuel tank 62 to the intake pipe 611. be.
The learning operation 504 is an operation of learning the opening degree of the sealing valve 3 in at least one of the vapor operation 501 and the purging operation 503.

Further, the control device 5 has an opening command unit 51, a valve opening start learning unit 52, and a valve opening threshold setting unit 53, and is opened when the sealing valve 3 is opened to perform the vapor operation 501 or the purge operation 503. The opening command amount K1 by the opening command unit 51 is determined based on the valve opening start amount K0 by the valve start learning unit 52.
The opening degree command unit 51 is a control portion that transmits an opening degree command amount K1 for determining the opening degree of the sealing valve 3 to the stepping motor 35.
The valve opening start learning unit 52 is based on the opening command amount K1 when the pressure P of the gas phase gas G starts to decrease when the opening command amount K1 is gradually increased from zero in the learning operation 504. This is a control site for learning the valve opening start amount K0.
The valve opening threshold setting unit 53 sets the valve opening threshold TH for determining that the pressure P of the gas phase gas G has started to decrease, and is the pressure P of the gas phase gas G before the time when the learning operation 504 is started. It is a control part set based on the pre-learning pressure P0.

Preferably, the control device 5 can have a pressure drop amount detecting unit 54. The pressure drop detection unit 54 controls to detect the pressure drop ΔP, which is a value obtained by subtracting the pressure P of the gas phase gas G when the opening command amount K1 is gradually increased from zero from the pre-learning pressure P0. It is a part. At this time, the valve opening start learning unit 52 performs the learning operation 504 when the internal combustion engine 61 is stopped or when the operation is started, and the pressure decrease amount ΔP detected by the pressure decrease amount detecting unit 54 is equal to or higher than the valve opening threshold value TH. When becomes, it can be determined that the pressure P of the gas phase gas has started to decrease.

Further, the control device 5 can have a relationship learning unit 55, an opening degree correction unit 56, a threshold map M, and a pressure relationship map M1 which is a relationship map.

The evaporative fuel processing apparatus 1 of this embodiment will be described in detail below.
(Evaporated fuel processing device 1)
As shown in FIG. 1, the evaporative fuel processing device 1 does not release the evaporative fuel F1 constituting the gas phase gas G in the fuel tank 62 into the atmosphere when the fuel F is replenished to the fuel tank 62 in the vehicle 6. Used to make. The evaporated fuel F1 in the fuel tank 62 is stored in the canister 2 and then discharged to the intake pipe 611 of the internal combustion engine 61, or bypasses the canister 2 and is discharged to the intake pipe 611 of the internal combustion engine 61. Then, the fuel component of the evaporated fuel F1 is used for combustion in the internal combustion engine 61.

The flow rate of the combustion air A supplied from the intake pipe 611 to the internal combustion engine 61 is adjusted by operating the throttle valve 612 arranged in the intake pipe 611. A fuel injection device 63 for injecting fuel F supplied from the fuel tank 62 is arranged in the internal combustion engine 61.

(Fuel tank 62)
As shown in FIG. 1, the fuel tank 62 stores the fuel F used for the combustion operation of the internal combustion engine 61. When the fuel tank 62 is supplied with the fuel F to the fuel filler port 621 used when the fuel F is refueled from the outside, the purge port 622 to which the vapor pipe 41 is connected, and the fuel injection device 63 of the internal combustion engine 61. A fuel pump 623 to be used is provided.

The refueling port 621 is provided with a cap that normally closes the refueling port 621 and opens the refueling port 621 during refueling. In the fuel tank 62, a sensor for detecting the pressure P of the gas phase gas G and stopping the refueling by the refueling nozzle is arranged. The fuel pump 623 supplies the fuel constituting the liquid phase of the fuel tank 62 to the fuel injection device 63.

(Canister 2)
As shown in FIG. 1, the canister 2 has a case 21 and an adsorbent 22 such as activated carbon, which is arranged in the case 21 and adsorbs the evaporated fuel (vaporized fuel) F1. The case 21 of the canister 2 is provided with a gas phase gas G inlet 211 connected to the vapor pipe 41, a fuel component outlet 212 connected to the purge pipe 42, and a pressure release port 213 that can be opened to the atmosphere. Has been done. The pressure release port 213 is provided with an on-off valve 23 for opening and closing the pressure release port 213 that can be opened to the atmosphere. When purging (exhausting) the gas phase gas G from the gas phase of the fuel tank 62 to the canister 2, the pressure relief port 213 is opened to the atmosphere by the on-off valve 23. Then, in the canister 2, the fuel component in the evaporated fuel F1 in the gas phase gas G is adsorbed on the adsorbent 22, and the pressure in the canister 2 becomes equal to the atmospheric pressure.

Further, the fuel component adsorbed on the adsorbent 22 of the canister 2 passes through the purge pipe 42 and is discharged to the intake pipe 611 of the internal combustion engine 61. At this time, the pressure relief port 213 of the canister 2 is opened to the atmosphere, and the purge pipe 42 is opened by the purge valve 43. Then, the fuel component adsorbed on the adsorbent 22 is generated by the internal combustion engine 61 by the air flow utilizing the differential pressure between the atmospheric pressure entering the canister 2 from the pressure relief port 213 and the negative pressure generated in the intake pipe 611. It is discharged to the intake pipe 611.

(Sealed valve 3)
As shown in FIGS. 3 and 4, the closed valve 3 of this embodiment includes a housing 31, a valve guide 32, a valve 33, a valve side spring 34, a stepping motor 35, and a guide side spring 36. The housing 31 constitutes the case of the closed valve 3, and has a closed flow path 311 connected to the vapor pipe 41. The valve guide 32 can advance and retreat with respect to the housing 31 by converting the rotational force of the stepping motor 35 into a propulsive force. The valve 33 is slidably engaged with the valve guide 32 to open and close the closed flow path 311 of the housing 31.

The valve-side spring 34 is sandwiched between the valve guide 32 and the valve 33, and urges the valve 33 in the direction of closing the closed flow path 311. The guide-side spring 36 is arranged on the outer periphery of the valve guide 32, and is for alleviating backlash that occurs between the output shaft 351 of the stepping motor 35 and the valve guide 32.

(Housing 31)
As shown in FIGS. 3 and 4, the housing 31 has an accommodating hole 310 accommodating the valve guide 32 and a closed flow path 311 communicating with the accommodating hole 310. The accommodating hole 310 is formed from the base end side L2 in the axial direction L of the housing 31. The closed flow path 311 has an inflow section 312 connected to the fuel tank 62 into which the gas phase gas G flows in, and an outflow section 314 in which the gas phase gas G flows out to the canister 2. The inflow portion 312 is formed parallel to the accommodating hole 310 at the tip end side L1 of the accommodating hole 310, and the outflow portion 314 is formed perpendicular to the accommodating hole 310.

(Axial direction L)
The axial direction L is a direction parallel to the direction in which the valve 33 opens and closes the closed flow path 311. In the axial direction L of the closed valve 3, the side on which the stepping motor 35 is arranged is called the base end side L2, and the side where the closed flow path 311 is blocked by the valve 33 is called the tip end side L1.

(Valve guide 32)
As shown in FIGS. 3 and 4, the valve guide 32 includes a central shaft portion 321 screwed into the output shaft 351 of the stepping motor 35, and a guide disk portion 322 formed around the central shaft portion 321. It has a guide cylinder portion 323 that protrudes from the peripheral edge portion of the guide disk portion 322 and is formed in a cylindrical shape, and a locking portion 323a that is formed on the inner peripheral surface of the guide cylinder portion 323 and locks the valve 33. A male screw 352 is formed on the outer circumference of the output shaft 351 of the stepping motor 35. A hollow hole 321a is formed in the center of the central shaft portion 321 of the valve guide 32, and a female screw 321b screwed into the screw 352 of the output shaft 351 of the stepping motor 35 is formed on the inner circumference of the hollow hole 321a. Is formed. The locking portion 323a is composed of a protruding portion protruding from the inner peripheral surface of the guide cylinder portion 323 toward the inner peripheral side. The main body of the stepping motor 35 is fixed to the housing 31.

(Valve 33)
As shown in FIGS. 3 and 4, the valve 33 is a valve cylinder provided with a locked projection 331a which is arranged on the inner peripheral side of the guide cylinder portion 323 of the valve guide 32 and is locked to the locking portion 323a. A ring-shaped sealing material 333 provided in the valve closing plate portion 332 and sealing the opening 313 of the closed flow path 311. Has. The valve cylinder portion 331 is formed in a cylindrical shape that guides the outer circumference of the valve side spring 34. The locked projection 331a is formed so as to project toward the outer peripheral side at the end of the valve cylinder portion 331 at the base end side L2 in the axial direction L. The valve closing plate portion 332 and the locked projection 331a are guided in the axial direction L by the inner circumference of the guide cylinder portion 323 of the valve guide 32.

The sealing material 333 is arranged at the peripheral edge of the opening 313 of the inflow portion 312 of the closed flow path 311 in the housing 31. On the tip end side L1 of the sealing material 333 in the axial direction L, a sealing portion 333a in the housing 31 that comes into contact with the peripheral edge of the opening 313 of the inflow portion 312 of the closed flow path 311 and elastically deforms is formed. .. The position of the tip end side L1 in the axial direction L of the entire circumference of the sealing portion 333a is in a virtual plane parallel to the surface of the base end side L2 in the axial direction L of the valve closing plate portion 332.

The valve 33 is urged to the tip end side L1 in the axial direction L by the valve side spring 34, and the locked projection 331a of the valve cylinder portion 331 of the valve 33 is the locking portion 323a of the guide cylinder portion 323 of the valve guide 32. It is maintained in the valve guide 32 by being locked by. As shown in FIG. 3, the valve 33 has a closing position 301 that closes the closed flow path 311 by receiving the urging force of the valve side spring 34, and as shown in FIG. 4, the base end of the valve guide 32 in the axial direction L. It is possible to move to the opening position 302 in which the opening amount of the closed flow path 311 is determined according to the moving amount to the side L2. The closing position 301 constitutes the initial position (normal position) of the valve 33, and in the normal state of the valve 33, the sealing flow path 311 is closed by the sealing material 333 of the valve 33.

As shown in FIG. 3, when the opening 313 of the inflow portion 312 of the closed flow path 311 is closed by the sealing portion 333a of the sealing material 333 of the valve 33, the valve side spring 34 tends to elastically recover. As a result, the force acting on the valve closing plate portion 332 on the tip end side L1 in the axial direction L acts on the valve closing plate portion 332 on the proximal end side L2 in the axial direction L due to the pressure due to the gas phase gas G in the inflow portion 312. It is greater than force. As a result, the valve 33 is maintained at the closed position 301, and the closed flow path 311 is maintained in the closed state.

On the other hand, as shown in FIG. 4, when the valve guide 32 is moved to the base end side L2 in the axial direction L by the stepping motor 35 in order to open the opening 313 of the inflow portion 312 of the closed flow path 311, the valve guide Along with 32, the valve 33 and the valve side spring 34 also move to the base end side L2 in the axial direction L. Then, the sealing portion 333a of the sealing material 333 of the valve 33 is separated from the peripheral edge of the opening 313 of the inflow portion 312 of the closed flow path 311 in the housing 31, the valve 33 moves to the opening position 302, and the closed flow Road 311 is opened. In this way, the amount of movement of the valve guide 32, the valve 33, and the valve side spring 34 to the base end side L2 in the axial direction L is determined according to the number of drive pulses energized in the stepping motor 35. Thereby, the opening amount of the closed flow path 311 is quantitatively determined.

(Valve side spring 34, guide side spring 36)
As shown in FIGS. 3 and 4, the valve-side spring 34 and the guide-side spring 36 are composed of a compression coil spring (torsion coil spring) in which a round wire as a wire is spirally twisted. The valve-side spring 34 applies a predetermined urging force to the valve 33 that closes the closed flow path 311 and uses this urging force to maintain the valve 33 at the closing position 301. The guide-side spring 36 is arranged on the outer periphery of the guide cylinder portion 323 of the valve guide 32. The guide-side spring 36 is sandwiched between the stepped portion 323b formed in the guide cylinder portion 323 and the peripheral edge portion of the opening 313 of the inflow portion 312 of the closed flow path 311 in the housing 31.

Since the valve guide 32 is urged to the base end side L2 in the axial direction L by the guide side spring 36, the screw 352 of the output shaft 351 of the stepping motor 35 and the center hole of the central shaft portion 321 of the valve guide 32 The gap between the female screw 321b and the female screw 321b is brought to one side in the axial direction L. As a result, when the output shaft 351 of the stepping motor 35 rotates, rattling (backlash) in the axial direction L between the output shaft 351 and the valve guide 32 is suppressed.

(Purge valve 43)
As shown in FIG. 1, the purge valve 43 purges (exhausts) the fuel component adsorbed on the adsorbent 22 of the canister 2 to the intake pipe 611 of the internal combustion engine 61, and the gas phase gas G of the fuel tank 62. The purge pipe 42 is configured to be opened when purging (discharging) to the intake pipe 611 of the internal combustion engine 61. The purge valve 43 of this embodiment has a function of opening and closing the purge pipe 42 on and off.

The purge valve 43 may be repeatedly opened and closed by a pulse-shaped energization command, and the on / off ratio in the pulse width may be modulated to quantitatively change the opening degree of opening the purge pipe 42. In this case, in the canister purge operation 502, the flow rate of the purge gas containing the fuel component flowing through the purge valve 43 can be appropriately adjusted. Further, the purge valve 43 can also be configured by a control valve capable of quantitatively changing the opening degree of opening the purge pipe 42.

(Pressure sensor 44)
As shown in FIG. 1, the pressure sensor 44 is composed of a pressure gauge that detects the pressure P of the gas phase gas G in the fuel tank 62. Most of the pressure P of the gas phase gas G in the fuel tank 62 is due to the vapor pressure of the evaporated fuel F1.

(Control device 5)
As shown in FIGS. 1 and 2, the control device 5 of the evaporative fuel processing device 1 is configured in the control device of the vehicle 6. The sealing valve 3, the purge valve 43, and the on-off valve 23 are connected to the control device 5 of the vehicle 6 as output devices, and can be opened and closed in response to a command from the control device 5. When a predetermined number of drive pulses are energized from the control device 5 to the stepping motor 35 in the closed valve 3, the valve 33 opens the opening 313 of the closed flow path 311. The pressure sensor 44 is connected to the control device 5 of the vehicle 6 as an input device, and can transmit the pressure P information to the control device 5.

Further, various environmental information regarding the internal environment of the fuel tank 62 or its surrounding environment can be transmitted to the control device 5 from various sensors and the like provided inside and outside the fuel tank 62. Such environmental information includes, for example, temperature information from the temperature sensor S1 that detects the temperature of the fuel tank 62 or its surroundings, and fuel remaining amount information from the liquid level sensor S2 that detects the remaining amount of fuel F in the fuel tank 62. , Volatile information of the fuel F determined from the type and properties of the fuel F of the fuel tank 62, travel history information of the vehicle 6, and the like. The temperature information and the remaining fuel amount information may be information estimated based on the operating state of the internal combustion engine 61 and the like.

The control device 5 of the evaporative fuel processing device 1 may be provided separately from the control device of the vehicle 6 and may be connected to the control device of the vehicle 6 so that data can be transmitted and received.

In the normal state of the internal combustion engine (engine) 61 of the vehicle 6, the supply amount (mass) of the combustion air A to the intake pipe 611 is adjusted by the opening degree of the throttle valve 612, and the fuel injection device 63 is injected. The amount (mass) of fuel F supplied to the internal combustion engine 61 is adjusted according to the amount. Then, the control device 5 controls the air-fuel ratio (A / F) as the supply amount of combustion air to the fuel supply amount so as to be the target air-fuel ratio.

When the evaporated fuel F1 is not purged from the fuel tank 62 or the canister 2 to the intake pipe 611, the fuel supply to the internal combustion engine 61 is only the supply of the injected fuel F2 by the fuel injection device 63. Feedback control is performed. When the vaporized fuel F1 is purged from the canister 2 or the fuel tank 62 to the intake pipe 611 of the internal combustion engine 61 by performing the purge operation 503 or the canister purge operation 502, the air-fuel ratio in the internal combustion engine 61 is adjusted. The control device 5 reduces the amount of fuel supplied from the fuel injection device 63 to the internal combustion engine 61.

(Each operation by the control device 5 501, 502, 503, 504)
The sealing operation by the control device 5 means an operation in which the valve 33 of the sealing valve 3 closes the opening 313 of the sealing flow path 311 to maintain the sealed state of the fuel tank 62. The sealing operation indicates that the rotation position of the output shaft 351 of the stepping motor 35 is held, and the state in which the valve 33 is in the closing position (initial position) 301 is maintained. In the normal state of the evaporative fuel processing device 1, the control device 5 is closed.

The vapor operation 501 by the control device 5 is performed when the gas phase gas G in the fuel tank 62 is purged to the canister 2 before the fuel tank 62 is refueled. When the vapor operation 501 is performed, the pressure P of the gas phase gas G in the fuel tank 62 is lowered, and when the fuel filler port 621 of the fuel tank 62 is opened, the evaporated fuel F1 in the gas phase gas G of the fuel tank 62 is opened. Is prevented from being released into the atmosphere.

The canister purge operation 502 by the control device 5 is performed when the fuel component adsorbed on the adsorbent 22 of the canister 2 is used for combustion of the air-fuel mixture of the fuel and the combustion air in the internal combustion engine 61.

In the purging operation 503 by the control device 5, the gas phase gas G in the fuel tank 62 is purged to the intake pipe 611 of the internal combustion engine 61 when the internal combustion engine 61 performs a combustion operation after the fuel tank 62 is refueled. It is done when you do. In the purge operation 503, the evaporated fuel F1 in the gas phase gas G passes through a part of the canister 2 without being adsorbed by the adsorbent 22 of the canister 2. By performing the purge operation 503, the pressure P of the gas phase gas G in the fuel tank 62 can be reduced during the combustion operation of the internal combustion engine 61.

The learning operation 504 by the control device 5 is performed by gradually increasing the opening command amount K1 from the opening command unit 51 to the stepping motor 35 from zero while the sealing operation by the control device 5 is being performed. .. Further, the learning operation 504 is performed in a process in which the pressure P of the gas phase gas G in the fuel tank 62 changes while the sealing operation is being performed.

By the learning operation 504, the fuel tank 62 is closed, that is, the valve 33 of the closed valve 3 closes the opening 313 of the closed flow path 311. When the valve 33 leaves the opening 313, the closed flow path 311 opens. Based on the change in the pressure P of the gas phase gas G in the fuel tank 62 at this time and the opening command amount K1, the relationship with the valve opening start amount K0 is learned. Further, in the case where the pressure P of the gas phase gas G before the start of the learning operation 504 is different, the pressure relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G is obtained by performing the learning operation 504. Map M1 is obtained.

(Specific configuration of control device 5)
As shown in FIG. 2, the control device 5 includes an opening command unit 51, a valve opening start learning unit 52, a valve opening threshold setting unit 53, a pressure drop amount detecting unit 54, a relationship learning unit 55, and an opening correction unit 56. Have. The control device 5 has a function of learning the valve opening start amount K0 as a dead zone generated in the closed valve 3 and a function of correcting the dead zone. The function of learning the dead zone is a function of learning the predetermined amount by paying attention to the fact that the closed valve 3 opens only when the command amount to the stepping motor 35 for driving the closed valve 3 reaches a predetermined amount. The function of correcting the dead zone is a function of performing correction that increases the command amount by the learned predetermined amount.

In the control device 5, the opening degree command unit 51 is configured to transmit the opening degree command amount K1 for determining the opening degree of the sealing valve 3 to the stepping motor 35. The valve opening start learning unit 52 has a function of learning the dead zone, and learns the valve opening start amount K0 based on the opening command amount K1 when the pressure P of the gas phase gas G starts to decrease. It is configured as.
In the present embodiment, when the pressure P of the gas phase gas G starts to decrease, when the closed valve 3 changes from the closed state to the open state, that is, when the valve opening start position of the closed valve 3 is reached. Can be.

The valve opening threshold setting unit 53 sets the valve opening threshold TH for determining that the pressure P of the gas phase gas G has started to decrease. The valve opening threshold TH is configured to be set by collating with the threshold map M stored in advance based on the pre-learning pressure P0, which is the pressure P of the gas phase gas G before the time when the learning operation 504 is started. ing.

The pressure drop detection unit 54 detects the pressure drop ΔP, which is the value obtained by subtracting the pressure P of the gas phase gas G when the opening command amount K1 is gradually increased from zero from the pre-learning pressure P0. It is configured. Then, the valve opening start learning unit 52 started to decrease the pressure P of the gas phase gas G when the pressure decrease amount ΔP detected by the pressure decrease amount detecting unit 54 became equal to or higher than the valve opening threshold value TH. Is determined.

In the learning operation 504, the relationship learning unit 55 receives a plurality of different pre-learning pressures P0 when the valve opening start learning unit 52 learns a plurality of different valve opening start amounts K0 corresponding to the plurality of different pre-learning pressures P0. Learn the relationship between the pressure P of the gas phase gas G corresponding to and the valve opening start amount K0. Then, it is configured to create a pressure relationship map M1 showing the relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G.

The opening degree correction unit 56 has a function of correcting the dead zone, and the pressure P of the gas phase gas G detected by the pressure sensor 44 when the sealing valve 3 is opened to perform the vapor operation 501 or the purge operation 503. The operating pressure Pa is collated with the pressure relationship map M1 to read the operating valve opening start amount Ka, which is the valve opening start amount K0 at this time, and the opening command amount K1 by the opening command unit 51 is used during operation. It is configured to be corrected by the valve opening start amount Ka.

(Opening command unit 51)
As shown in FIG. 2, the opening command unit 51 of the control device 5 is for driving the stepping motor 35 of the sealing valve 3 as the opening command amount K1 in the vapor operation 501, the purging operation 503, and the learning operation 504. A predetermined number of drive pulses are transmitted to the stepping motor 35. The opening command amount K1 by the opening command unit 51 is determined by the number of drive pulses for driving the stepping motor 35. The output shaft 351 of the stepping motor 35 is rotated by a predetermined angle by the drive pulse transmitted to the stepping motor 35, and the valve guide 32, the valve 33, and the valve side spring 34 are stroked in the axial direction L by a predetermined amount accordingly. Moving.

As shown in FIGS. 3 and 4, the opening degree of the closed valve 3 is determined according to the number of pulses transmitted to the stepping motor 35. However, the closed valve 3 has a dead zone, and in the dead zone, the valve 33 actually closes even if the stepping motor 35 is energized in a stepped manner while the valve 33 of the closed valve 3 is in the closing position 301. The total number of pulses that do not move from position 301, in other words, the number of pulses transmitted while the sealing material 333 of the valve 33 does not separate from the closed flow path 311 and the pressure P of the gas phase gas G does not start to decrease. Expressed as a value. Further, the number of pulses in the dead zone is expressed as the valve opening start amount K0 of the closed valve 3.

As shown in FIG. 5, the valve opening start amount K0 compensates for the dead zone of the closed valve 3, and the valve opening start amount K0 is added to the opening command amount K1 by the opening command unit 51 to open the valve. The command amount K1 makes it possible to change the opening degree of the closed valve 3 proportionally from zero. The opening command unit 51 determines the opening command amount K1 so that the gas phase gas G of the target flow rate flows through the closed valve 3 in the vapor operation 501 and the purge operation 503.

At this time, the valve opening start amount K0 also changes depending on the pressure P of the gas phase gas G, and the relationship between the opening command amount K1 and the opening degree of the closed valve 3 changes. Therefore, the valve opening start amount K0 can also be regarded as an opening degree correction amount for correcting the opening degree command amount K1 by the opening degree commanding unit 51. In that case, the valve opening start amount K0 as the opening degree correction amount changes according to the pressure P of the gas phase gas G.

(Pressure relationship map M1)
As shown in FIG. 6, in the pressure relationship map M1 between the valve opening start amount K0 and the pressure P of the gas phase gas G, the valve opening start amount K0 is the pressure P of the gas phase gas G detected by the pressure sensor 44. The higher it is, the smaller it becomes. In other words, the lower the pressure P of the detected gas phase gas G, the larger the dead zone of the sealing valve 3, and the more difficult it is for the sealing valve 3 to open. The pressure relationship map M1 is used to correct the opening command amount K1 by using the valve opening start amount K0 after the use of the vehicle 6 and the evaporated fuel processing device 1 is started. An initial map can also be created by repeating the learning operation 504 when or prior to the start of use to learn the relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G. After the use is started, the valve opening start amount K0 can be learned and the pressure relationship map M1 can be updated by performing the learning operation 504 in a timely manner.

(Valve opening start learning unit 52)
As shown in FIGS. 3 and 4, the valve opening start learning unit 52 is a stepping motor from the opening command unit 51 in a state where the valve 33 is in the closing position (initial position) 301 when the learning operation 504 is performed. The opening command amount K1 transmitted to 35 and the pressure P of the gas phase gas G received from the pressure sensor 44 are monitored, and the valve opening start amount K0 is learned from the change. Specifically, the opening command amount K1 is gradually increased from zero, and when the amount of decrease in the pressure P of the gas phase gas G becomes equal to or more than a predetermined value, the pressure P of the gas phase gas G decreases. Is determined to have started. Then, the opening command amount K1 when the pressure P of the gas phase gas G starts to decrease can be set to the valve opening start amount K0.

For example, in the vapor operation 501, when purging from the fuel tank 62 to the canister 2, if the flow rate of the gas phase gas G is too small, it takes time to purge the gas phase gas G, and if it is too large, it evaporates in the gas phase gas G. A large amount of fuel F1 is adsorbed on the adsorbent 22. Therefore, it is necessary to accurately learn the valve opening start amount K0 corresponding to the dead zone of the closed valve 3 and appropriately set the opening degree of the closed valve 3. The learning operation 504 can be executed at the vapor operation 501 or the purge operation 503 for opening the closed valve 3, and by increasing the learning opportunities, the valve opening start amount K0 at the pressure P of a plurality of different gas phase gases G is learned. Therefore, it can be reflected in the pressure relationship map M1.

Preferably, the valve opening start learning unit 52 can perform the learning operation 504 when the internal combustion engine 61 is stopped or when the operation is started. When the internal combustion engine 61 is stopped, for example, the vapor operation 501 is executed when the vehicle is stopped and refueled. Further, when the ignition switch is turned on at the start of operation and the operation is started, the vapor operation 501 can be executed for the learning operation 504 to learn the valve opening start amount K0. In each of these cases, since the vehicle 6 is stopped, the influence of the pressure fluctuation due to the traveling of the vehicle can be suppressed. The learning operation 504 can also be performed when the sealing valve 3 is opened to perform the purging operation 503 during traveling, and the learning opportunity can be increased.

(Valve opening threshold setting unit 53)
As shown in FIGS. 7 and 8, the valve opening threshold setting unit 53 learns the valve opening threshold TH, which is a predetermined value for determining that the pressure P of the gas phase gas G has started to decrease, as a variable value. It is set according to the pre-learning pressure P0 before the time when the operation 504 is started. The pre-learning pressure P0 is the pressure P of the gas phase gas G when the fuel tank 62 is in the sealed state before the opening command amount K1 increases from zero, and is a reference for calculating the amount of decrease in the pressure P. It becomes a value. The pre-learning pressure P0 may be a value obtained by averaging the pressures P of a plurality of gas phase gases G received from the pressure sensor 44 in a predetermined section immediately before starting the learning operation 504, and reduces the influence of the pulsating component. can do.

When performing the learning operation 504, it is desirable that the pressure P of the gas phase gas G received from the pressure sensor 44 is in a stable state. However, since gasoline used as fuel contains a highly volatile component, as shown in FIG. 7, the pressure P of the gas phase gas G tends to pulsate due to the influence of the remaining amount of gasoline and the surrounding environment. Further, it was found that this pulsation amount tends to increase as the pre-learning pressure P0 increases. Therefore, when a constant valve opening threshold TH is used, the pressure drop due to pulsation is prevented from opening the closed valve 3. There was a risk that it would be erroneously determined to start, or that it would take too long to reduce the pressure.

Therefore, as shown in FIG. 8, the valve opening threshold TH is set so that the higher the pre-learning pressure P0, the larger the value. Here, as described below, the pressure region A that can be taken by the pre-learning pressure P0 is divided into three pressure regions A1, A2, and A3 (A2>A1> A3), and the corresponding three-step valve opening thresholds correspond to each. TH1, TH2, and TH3 (TH2>TH1> TH3) are defined.
Pressure region A1 (standard): TH1
Pressure region A2 (high pressure): TH2
Pressure region A3 (low pressure): TH3
When the pre-learning pressure P0 is in the standard pressure region A1, the standard valve opening threshold TH1 is selected, and when it is in the higher pressure region A2, the valve opening threshold TH2 larger than the valve opening threshold TH1 is selected and lower. When in the pressure region A3, a valve opening threshold TH3 smaller than the valve opening threshold TH1 is selected. The three pressure regions A take into account the magnitude of the pressure pulsation, and the pressure pulsation is also larger (for example, ± 20 kPa) in the pressure region A2 than the standard pressure region A1 (for example, ± 10 kPa). In region A3 the pressure pulsation is smaller (eg ± 5 kPa).

(Pressure drop detection unit 54)
The pressure drop amount detection unit 54 detects the pressure drop amount ΔP from the pre-learning pressure P0 when the opening command amount K1 is gradually increased from zero by the learning operation 504. The pressure drop amount ΔP is calculated as a value obtained by subtracting the pressure P of the gas phase gas G when the opening command amount K1 is gradually increased from zero from the pre-learning pressure P0 (that is, ΔP = P0-P). ). The valve opening start learning unit 52 compares the valve opening thresholds TH1 to TH3 set according to the pre-learning pressure P0 with the pressure decrease amount ΔP detected at any time while increasing the opening command amount K1 to reduce the pressure. When the amount ΔP becomes equal to or higher than the valve opening threshold value TH1 to TH3 (that is, ΔP ≧ TH1 to TH3), it is determined that the valve opening is started.

As shown in FIG. 7, in the pressure regions A1, A2, and A3, the stroke amount of the valve 33 corresponding to the opening command amount K1 of the closed valve 3 is gradually increased from the time point 1 to the time point 2, respectively. Then, when the valve 33 reaches the stroke amount that can be separated from the closing position 301 after the time point 2, the valve opening start determination position by the valve opening threshold TH is compared.
As described above, since the valve opening start amount K0 of the closed valve 3 changes depending on the magnitude of the pressure P (pre-learning pressure P0) of the gas phase gas G, the pressure drop starts in different pressure regions A. The timing will also be different, but for the sake of explanation, the deviation of the valve opening start position due to the difference in the pressure regions A1, A2, and A3 is ignored, and the comparison is made with the timing of the pressure drop aligned. There is.

For example, when the constant valve opening threshold TH is set to a size that does not malfunction in the pulsation amount of the standard pressure region A1, when the stroke amount of the valve 33 corresponding to the opening command amount K1 is gradually increased, the time point At 2, when the pressure P of the gas phase gas G begins to decrease, the pressure decrease amount ΔP reaches the valve opening threshold TH at the time point 3 immediately after the time point 2, and the valve opening determination is made promptly. On the other hand, in the higher pressure region A2, although the closed state of the closed valve 3 is maintained until the time point 2, at the time point 1, the pressure drop due to the pulsation is erroneously determined to be due to the start of valve opening. Further, in the lower pressure region A3, even if the pressure starts to decrease at the original valve opening start position, the determination is not made until the time point 4 which greatly exceeds the time point 3 because the pressure drop amount is small.

On the other hand, as shown in FIG. 8, when the valve opening thresholds TH1 to TH3 corresponding to the pre-learning pressure P0 are set in the pressure regions A1, A2, and A3, the original valve opening starts. The judgment is made in the vicinity of the position. For example, in the higher pressure region A2, a larger valve opening threshold TH2 is set according to the pulsation amount. Therefore, when the stroke amount of the valve 33 corresponding to the opening command amount K1 is gradually increased, the time point 2 is set. The pressure drop amount ΔP does not reach the valve opening threshold TH2 until it exceeds and begins to fall. Further, in the lower pressure region A3, the valve opening threshold value TH3 is set smaller according to the amount of pulsation. Therefore, when the pressure region A3 starts to decrease beyond the time point 2, the valve opening threshold value TH3 is quickly reached.

In this way, a plurality of pressure regions A1 to A3 corresponding to the pre-learning pressure P0 and a plurality of valve opening thresholds TH1 to TH3 corresponding to each are set, and these relationships are learned in advance and stored as a threshold map M. Can be done. The valve opening start learning unit 52 reads the valve opening thresholds TH1 to TH3 corresponding to the pre-learning pressure by collating with the threshold map M, and performs the learning operation 504 to prevent erroneous determination and to prevent the valve opening start amount. K0 can be learned accurately.

Specifically, for each pressure region A1 to A3, a reference pre-learning pressure P0 is set in advance (for example, the median value of each pressure region), and from the maximum value Pmax and the minimum value Pmin in the pressure pulsation waveform in that case. The larger the pulsation amount, which is the difference between them, the larger the valve opening threshold TH is set. For example, a value that is half of the pulsation amount is set as a pulsation component ΔPu (that is, ΔPu = (Pmax−Pmin) / 2), and is set to a value larger than this pulsation component ΔPu. Preferably, the valve opening threshold TH can be set by adding a predetermined margin α to the pulsating component ΔPu as described in the following equation.
TH = ΔPu + α = (Pmax-Pmin) / 2) + α

When creating the threshold map M, not only the three regions A1 to A3 but also an arbitrary number of pressure regions A are provided, and the valve opening threshold TH in consideration of the pressure pulsation is set for each of them. Just do it. The pressure at the boundary of each region is not particularly limited and can be appropriately set. Further, as shown in FIG. 8, the threshold map M learns the relationship between the pressure P of the gas phase gas G, which is the pre-learning pressure P0, and the valve opening threshold TH, and stores it as a relational expression or the like based on the result. You can also keep it. In that case, the valve opening threshold TH is calculated based on the pre-learning pressure P0 and the relational expression.

Further, the valve opening threshold setting unit 53 corrects the valve opening threshold TH set by using the pre-learning pressure P0 as a correction threshold corrected based on at least one of the environmental information inside and outside the fuel tank 62 that affects the pressure pulsation. It can also be set. As the environmental information, at least one of the temperature of the fuel tank 62, the remaining amount of fuel in the fuel tank 62, and the fuel properties in the fuel tank 62 can be used. Further, the environmental information is not limited to these, and for example, when the learning operation 504 is performed immediately after or during the running of the vehicle 6, the road surface state of the traveling path of the vehicle 6 or the operating state of the internal combustion engine 61, etc. It is also possible to correct the valve opening threshold TH based on.

As shown in FIG. 2, these environmental information is based on the information from various sensors input to the control device 5 and the information from the control device of the vehicle 6. Of these environmental information, the temperature of the fuel tank 62 can be detected or estimated using the temperature sensor S1 arranged around the fuel tank 62, and the remaining amount of fuel in the fuel tank 62 can be detected in the fuel tank 62. It can be detected by using the liquid level sensor S2 installed. The fuel properties in the fuel tank 62 are properties that affect the pressure P of the gas phase gas G, such as the volatility of the fuel F, and can be obtained from the control device of the vehicle 6 as fuel information according to the internal combustion engine 61. can.

All of these changes in environmental information act in the direction of changing the pressure P of the gas phase gas G in the fuel tank 62, and affect the magnitude of the pressure pulsation. The magnitude of this pressure pulsation increases as the temperature of the fuel tank 62 increases, and increases as the amount of fuel remaining in the fuel tank 62 increases. Further, the higher the volatility of the fuel F in the fuel tank 62, the larger the magnitude of the pressure pulsation.

Therefore, as shown in FIG. 9, the valve opening threshold TH corresponding to the pressure P of the gas phase gas G, which is the pre-learning pressure P0, is set, and these environmental informations are detected, and the valve opening threshold is set according to the magnitude thereof. The TH-corrected correction threshold value can be used for learning in the valve opening start learning unit 52. In that case, for each of these environmental information, a standard region, that is, a region that does not need to be corrected with respect to the standard characteristic line indicating the relationship between the pressure P of the gas phase gas G and the valve opening threshold TH is set. The standard valve opening threshold TH is corrected when the pressure pulsation is greater than or less than the standard region. Specifically, by making a correction to further increase or decrease the standard valve opening threshold TH according to the number and size of environmental information affecting the pressure pulsation, the determination of the valve opening start due to the pressure pulsation can be made more quickly. It will be possible to do it with high accuracy.

(Relationship Learning Department 55)
As shown in FIG. 6, the relationship learning unit 55 of the control device 5 sets the opening command amount K1 of the gas phase gas G by the opening command unit 51 after the use of the vehicle 6 and the evaporated fuel processing device 1 is started. It is constructed to compensate by pressure P. The relationship learning unit 55 starts valve opening learned by the valve opening start learning unit 52 in a plurality of cases where the pressure P of the gas phase gas G, which is the pre-learning pressure P0, is different in the state where the valve 33 is in the closed position 301. Using the amount K0, the relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G is learned. Then, the pressure relationship map M1 between the valve opening start amount K0 and the pressure P of the gas phase gas G is created or updated.

As shown in FIGS. 3 and 4, the pressure P of the gas phase gas G acting on the inflow portion 312 of the closed flow path 311 is higher than the pressure in the canister 2 acting on the outflow portion 314 of the closed flow path 311. A pressure is applied to the valve 33 so that the valve 33 moves to the proximal end side L2 in the axial direction L. Then, as the pressure P of the gas phase gas G increases, the pressure for moving the valve 33 to the proximal end side L2 in the axial direction L increases. Therefore, the valve opening start amount K0 of the on-off valve 23 by the valve opening start learning unit 52 is detected as the pressure P of the gas phase gas G increases.

(Opening correction unit 56)
As shown in FIG. 5, the opening degree correction unit 56 of the control device 5 corrects the opening degree command amount K1 by the opening degree commanding unit 51 by adding the valve opening start amount K0. Then, even if the opening degree of the sealing valve 3 is not directly detected, the opening degree correction unit 56 corrects the error factor due to the dead zone of the sealing valve 3 and brings the opening degree of the sealing valve 3 closer to the target opening degree. , The flow rate of the gas phase gas G passing through the closed valve 3 is controlled to an appropriate flow rate.

As shown in FIG. 6, the opening degree correction unit 56 uses the pressure relationship map M1 between the valve opening start amount K0 and the pressure P of the gas phase gas G when performing either the vapor operation 501 or the purge operation 503. Then, the opening command amount K1 by the opening command unit 51 is corrected. When performing the vapor operation 501 and the purge operation 503, the opening degree correction unit 56 detects the operating pressure Pa, which is the pressure P of the gas phase gas G, by the pressure sensor 44 when the vapor pipe 41 is opened by the sealing valve 3. do.

Next, the opening degree correction unit 56 collates the operating pressure Pa with the pressure relationship map M1 and reads the operating valve opening start amount Ka, which is the valve opening start amount K0 corresponding to the operating pressure Pa. Next, when the opening degree commanding unit 51 transmits the opening degree commanding amount K1 to the stepping motor 35 of the sealing valve 3, the opening degree correction unit 56 adds the valve opening start amount Ka during operation to the opening degree commanding amount K1. Make corrections. In other words, the opening degree correction unit 56 opens the valve during operation by changing the number of pulses as the opening degree command amount K1 transmitted from the opening degree commanding unit 51 to the stepping motor 35 to the number of pulses corresponding to the opening degree command amount K1. The number of pulses is corrected by adding the number of pulses corresponding to the starting amount Ka.

In this way, as shown in FIG. 5, the opening degree correction unit 56 adds the valve opening start amount Ka during operation to the opening degree command amount K1 based on the target opening degree as the target value X of the opening degree of the closed valve 3. The corrected opening command amount K2 is obtained. Then, in the vapor operation 501 and the purge operation 503, when the vapor pipe 41 is opened by the sealing valve 3, the corrected opening command amount K2 is transmitted from the opening command unit 51 to the stepping motor 35 of the sealing valve 3, and the sealing valve The opening degree of 3 is determined.

(Control of Evaporative Fuel Processing Device 1)
As shown in FIG. 1, in the vehicle 6, when the control device 5 performs a sealing operation, the opening degree of the sealing valve 3 is zero, and the valve 33 closes the sealing flow path 311 of the housing 31, the fuel tank 62 is used. The vapor pipe 41 to the canister 2 is blocked. Then, the pressure P of the gas phase gas G in the fuel tank 62 is appropriately increased. The learning operation 504, the vapor operation 501, the canister purge operation 502, and the purge operation 503 will be described below with reference to the flowchart.

(Learning operation 504)
As shown in the flowchart of FIG. 10, when the opening degree of the closed valve 3 is zero, the control device 5 performs the learning operation 504. In the learning operation 504, the pressure P of the gas phase gas G is detected by the pressure sensor 44 (step S101). Then, the relationship learning unit 55 of the control device 5 determines whether or not the detected pressure P of the gas phase gas G is suitable for creating the pressure relationship map M1 (step S102). This determination is performed in order to obtain the relationship between the pressure P of a plurality of different gas phase gases G and the valve opening start amount K0 as the pressure relationship map M1.

When the detected pressure P of the gas phase gas G is suitable for creating the pressure relationship map M1, the valve opening start amount routine by the valve opening start learning unit 52 of the control device 5 is executed (step S103). As shown in the flowchart of FIG. 11, in the valve opening start amount routine, first, the pressure of the gas phase gas G detected in the state where the opening command unit 51 of the control device 5 sets the opening command amount K1 to zero. P is read as the pre-learning pressure P0 (step S111). The pre-learning pressure P0 is, for example, the pressure P of the gas phase gas G detected in step S101. Next, the valve opening threshold setting unit 53 of the control device 5 sets the valve opening threshold TH by collating the pre-learning pressure P0 with the threshold map M (step S112).

After that, the opening command unit 51 of the control device 5 increases the opening command amount K1 by a predetermined amount (step S113). Subsequently, the pressure P of the gas phase gas G is detected by the pressure sensor 44 (step S114), and the pressure drop detection unit 54 of the control device 5 subtracts the pressure P of the gas phase gas G from the pre-learning pressure P0. , The pressure drop amount ΔP (= P0-P) is calculated.

The valve opening start learning unit 52 of the control device 5 compares the pressure decrease amount ΔP with the valve opening threshold value TH, and determines whether or not the pressure decrease amount ΔP is equal to or greater than the valve opening threshold value TH (step S115). When ΔP ≧ TH, it is determined that the pressure P of the gas phase gas G has started to decrease, and the opening command amount K1 at this time is set to the valve opening start amount K0 (step S116). When ΔP <TH, it is determined that the decrease in the pressure P of the gas phase gas G has not started yet, the opening command amount K1 is increased, the pressure decrease amount ΔP is calculated, and the pressure P is compared with the valve opening threshold TH. This is repeated (steps S113 to 115).

In this way, the valve opening start position is learned based on the pressure drop amount ΔP of the pressure P of the gas phase gas G, and the relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G is a part of the pressure relationship map M1. (Step S117).

After that, as shown in the flowchart of FIG. 10, the detection of the pressure P of the gas phase gas G by the pressure sensor 44 is continued (step S101). Further, the relationship learning unit 55 determines whether or not the detected pressure P of the gas phase gas G is suitable for creating the pressure relationship map M1 (step S102). Then, when the pressures P of the plurality of different gas phase gases G are detected, the valve opening start amount routine is repeatedly performed (steps S103, S111 to S117).

In this way, until the learning operation 504 is completed (step S104), the relationship between the valve opening start amount K0 and the pressure P of the gas phase gas G is acquired in a range in which the pressure P of the gas phase gas G is appropriately different. (Step S117), a pressure relationship map M1 between the valve opening start amount K0 and the pressure P of the gas phase gas G is created.

(Vapor operation 501)
When refueling the fuel tank 62 with the fuel F, the occupant of the vehicle 6 pushes the refueling switch provided in the vehicle interior. Then, when the operation time is recognized by receiving the operation of the refueling switch and the vapor operation 501 is performed by the control device 5, the opening degree correction unit 56 uses the pressure relationship map M1 to open the opening degree by the opening degree command unit 51. Correct the command amount K1.

Specifically, as shown in the flowchart of FIG. 12, it is determined whether or not the vapor operation 501 is performed depending on the presence or absence of the input of the refueling switch (step S201). When the refueling switch is pressed, the operating time is recognized, and the operating pressure Pa as the pressure P of the gas phase gas G during operating is detected by the pressure sensor 44 (step S202).

Next, as shown in FIG. 6, the operating pressure Pa is collated with the pressure relationship map M1, and the operating valve opening start amount Ka, which is the valve opening start amount K0 corresponding to the operating pressure Pa, is from the pressure relationship map M1. Read (step S203). Then, as shown in FIG. 5, the opening command amount K1 by the opening command unit 51 is the corrected opening degree obtained by adding the valve opening start amount Ka during operation to the opening degree command amount K1 corresponding to the target opening degree. It is determined as the command amount K2 (step S204). The target opening degree is determined according to the target flow rate of the gas phase gas G purged from the fuel tank 62 to the canister 2.

Next, the corrected opening command amount K2 is transmitted from the opening command unit 51 to the stepping motor 35 of the sealing valve 3, and the vapor piping 41 is opened by the sealing valve 3 (step S205). Further, in response to a command from the control device 5, the pressure release port 213 is opened by the onboard valve 23 of the canister 2 (step S206). In this way, the gas phase gas G flowing through the closed valve 3 is controlled to the target flow rate, and the gas phase gas G is purged from the fuel tank 62 to the canister 2 via the vapor pipe 41 (step S207). At this time, due to the difference between the pressure P due to the gas phase gas G in the fuel tank 62 and the pressure in the canister 2, the gas phase gas G in the fuel tank 62 flows to the canister 2, and the evaporated fuel contained in the gas phase gas G. The fuel component of F1 is adsorbed on the adsorbent 22 of the canister 2.

After that, the pressure P of the gas phase gas G is detected by the pressure sensor 44 (step S208), and it is determined whether or not the pressure P of the gas phase gas G has dropped to a predetermined pressure or less (step S209). When the pressure P of the gas phase gas G drops below a predetermined pressure, the vapor sealing valve 3 closes the vapor pipe 41 (step S210). Further, the pressure relief port 213 of the canister 2 is closed by the on-off valve 23 (step S211). In this way, the vapor operation 501 is completed, the fuel filler port 621 is opened by the control device 5, and the occupant of the vehicle 6 can refuel the fuel tank 62 from the fuel filler port 621.

Further, when the occupant or the like of the vehicle 6 refuels the fuel F to the fuel tank 62, the sealing valve 3 may have the vapor pipe 41 open, and the on-off valve 23 may have the pressure relief port 213 of the canister 2 open. can.

(Canister purge operation 502)
The canister purge operation 502 is performed to purge the fuel component adsorbed on the adsorbent 22 of the canister 2 to the intake pipe 611 of the internal combustion engine 61 when the combustion operation of the internal combustion engine 61 is performed. The timing at which the canister purge operation 502 is performed is appropriately determined by the control device 5 of the internal combustion engine 61.

Specifically, as shown in the flowchart of FIG. 13, when the fuel component adsorbed on the adsorbent 22 is purged from the canister 2 to the intake pipe 611 of the internal combustion engine 61, the canister 2 is depressurized by the on-off valve 23. At the same time as the opening 213 is opened (step S301), the purge pipe 42 is opened by the purge valve 43 (step S302). At this time, the canister 2 is connected to the intake pipe 611 of the internal combustion engine 61 via the purge pipe 42. Then, the fuel component in the adsorbent 22 flows to the intake pipe 611 due to the difference between the pressure in the canister 2 (atmospheric pressure) and the pressure in the intake pipe 611 of the internal combustion engine 61 (negative pressure). Then, the fuel component separated from the adsorbent 22 is used for the combustion operation of the internal combustion engine 61 together with the fuel F injected into the internal combustion engine 61.

Next, it is determined whether or not the on-off valve 23 and the purge valve 43 have been opened and a predetermined time has elapsed (step S303). After the predetermined time has elapsed, the onboard valve 23 closes the pressure relief port 213 of the canister 2 (step S304), and the purge valve 43 closes the purge pipe 42 (step S305). In this way, the canister purge operation 502 is completed, and the fuel component adsorbed on the adsorbent 22 of the canister 2 is used for the combustion operation of the internal combustion engine 61.

(Purge operation 503)
As shown in the flowchart of FIG. 14, when the combustion operation of the internal combustion engine 61 is performed, the fuel tank 62 is normally sealed by the sealing valve 3. Further, the pressure sensor 44 of the fuel tank 62 continues to detect the pressure P of the gas phase gas G (step S401). Then, it is determined whether or not the pressure P of the gas phase gas G becomes equal to or higher than the predetermined pressure (step S402). When the pressure P of the gas phase gas G becomes equal to or higher than a predetermined pressure, the operation time is recognized and the purging operation 503 by the control device 5 is performed.

Specifically, the opening degree setting routine (step S403) is executed. As shown in the flowchart of FIG. 15, in the opening degree setting routine, the operating pressure Pa as the pressure P of the operating gas phase gas G is detected by the pressure sensor 44 (step S421). Next, as shown in FIG. 6, the operating pressure Pa is collated with the pressure relationship map M1, and the operating valve opening start amount Ka, which is the valve opening start amount K0 corresponding to the operating pressure Pa, is from the pressure relationship map M1. Read (step S422).

Next, the opening degree of the sealing valve 3 for obtaining the target flow rate is determined based on the pressure P of the gas phase gas G and the target flow rate of the gas phase gas G flowing through the sealing valve 3 (step S423). The target flow rate of the gas phase gas G flowing through the closed valve 3 is set to a flow rate suitable for controlling the air-fuel ratio of the internal combustion engine 61. Next, as shown in FIG. 5, the opening command amount K1 by the opening command unit 51 is corrected by adding the valve opening start amount Ka during operation to the opening command amount K1 corresponding to the opening of the closed valve 3. It is determined as the rear opening command amount K2 (step S424).

Next, the corrected opening command amount K2 is transmitted from the opening command unit 51 to the stepping motor 35 of the sealing valve 3, and the vapor piping 41 is opened by the sealing valve 3 (step S404). Further, in response to a command from the control device 5, the purge pipe 42 is opened by the purge valve 43 (step S405). After the purge pipe 42 is opened by the purge valve 43, the vapor pipe 41 may be opened by the closed valve 3. Further, when the purge pipe 42 is opened by the purge valve 43, the pressure release port 213 of the canister 2 may be opened by the on-off valve 23.

In this way, the gas phase gas G flowing through the closed valve 3 and the purge valve 43 is controlled to the target flow rate, and the intake pipe of the internal combustion engine 61 is controlled from the gas phase gas G of the fuel tank 62 via the vapor pipe 41 and the purge pipe 42. The gas phase gas G is purged to 611 (step S406). At this time, the gas in the fuel tank 62 flows to the intake pipe 611 of the internal combustion engine 61 due to the difference between the pressure P due to the gas phase gas G in the fuel tank 62 and the pressure in the intake pipe 611.

Further, in the purging operation 503 and the canister purging operation 502, the injection fuel F2 is supplied by the fuel injection device 63 in the internal combustion engine 61 before the gas phase gas G is purged from the evaporative fuel processing device 1 to the intake pipe 611. Therefore, feedback control is performed by the control device 5 so that the air-fuel ratio becomes the target air-fuel ratio.

Next, the pressure sensor 44 detects the pressure P of the gas phase gas G (step S407), and determines whether or not the pressure P of the gas phase gas G has dropped by a predetermined amount or more (step S408). When the pressure P of the gas phase gas G drops by a predetermined amount or more, the opening degree setting routine (step S409) is executed again.

Further, when the pressure P of the gas phase gas G is detected by the pressure sensor 44, it is determined whether or not the pressure P of the gas phase gas G has dropped to a predetermined pressure or less (step S410). When the pressure P of the gas phase gas G becomes equal to or lower than the predetermined pressure, the vapor piping 41 is closed by the sealing valve 3 (step S411). Further, the purge pipe 42 is closed by the purge valve 43 (step S412). In this way, the purging operation 503 is completed, and the gas phase gas G generated in the fuel tank 62 is used for the combustion operation of the internal combustion engine 61.

(Update of pressure-related map M1, etc.)
In the present embodiment, the flowcharts (FIGS. 10 to 15) in which each operation 501 to 504 by the control device 5 is performed separately are shown, but the present invention is not limited thereto. The learning operation 504 can be continuously performed not only before the vapor operation 501, the canister purge operation 502, and the purge operation 503 are performed, but also after each of these operations 501, 502, and 503 is performed. The learning operation 504 can be performed at an appropriate timing during the sealing operation of the control device 5 in which the fuel tank 62 is sealed by the sealing valve 3. Further, the learning operation 504 can be performed between the vapor operation 501 and the canister purge operation 502, between the canister purge operation 502 and the purge operation 503, between the purge operation 503 and the vapor operation 501, and the like.

Further, the vapor operation 501 or the purge operation 503 can be performed before the pressure relationship map M1 is created by the learning operation 504. In this case, the opening degree correction unit 56 temporarily uses the relationship map initially set in the control device 5, and after the pressure relationship map M1 is created by the subsequent learning operation 504, the created pressure. The relationship map M1 can be used. The pressure relationship map M1 can be updated as appropriate each time the learning operation 504 is performed.

(Action effect)
In the evaporative fuel processing apparatus 1 of the present embodiment, when the closed valve 3 learns the valve opening start amount K0 when the purge pipe 41 is actually opened by the operation of the stepping motor 35, the pressure decrease amount from the pre-learning pressure P0. Use ΔP. As a result, the influence of pressure pulsation can be reduced, and accurate learning becomes possible, and the opening command amount K1 for determining the opening degree of the closed valve 3 can be appropriately corrected using the result. Further, by learning the relationship between the plurality of valve opening start amounts K0 and the pressure P of the gas phase gas G corresponding to the plurality of pre-learning pressures P0, the pressure between the valve opening start amount K0 and the pressure P of the gas phase gas G The relationship map M1 can be created.

Therefore, according to the evaporative fuel processing device 1 of the present embodiment, when the evaporative fuel F1 is purged to the canister 2 or the intake pipe 611 by controlling the closed valve 3 in the vapor operation 501 and the purge operation 503 to the target opening degree. , The purge flow rate of the evaporated fuel F1 from the fuel tank 62 can be controlled more appropriately and quantitatively.

The present invention is not limited to the above-described embodiments, and further different embodiments can be configured without departing from the gist thereof. The present invention also includes various modifications, modifications within an equal range, and the like. Further, the technical idea of the present invention also includes combinations, forms, etc. of various components assumed from the present invention.

1 Evaporated fuel processing device 2 Canister 3 Sealed valve 41 Vapor piping 42 Purge piping 43 Purge valve 44 Pressure sensor 5 Control device 61 Internal combustion engine 62 Fuel tank

Claims (6)

An evaporative fuel processing apparatus (1) provided in a vehicle (6) having an internal combustion engine (61) and a fuel tank (62) to process the evaporated fuel (F1) in which the fuel in the fuel tank has evaporated.
A canister (2) having an adsorbent (22) for adsorbing the evaporated fuel,
A closed valve (3) provided in the vapor pipe (41) connected from the fuel tank to the canister, and the opening degree of opening and closing the vapor pipe can be quantitatively adjusted by an actuator (35).
A pressure sensor (44) provided in the fuel tank to detect the pressure (P) of the gas phase gas in the fuel tank, and
A purge valve (43) provided in a purge pipe (42) connected from the canister to the intake pipe (611) of the internal combustion engine to open and close the purge pipe.
A sealing operation of closing the vapor pipe by the sealing valve to seal the fuel tank, and a vapor operation of opening the vapor pipe by the sealing valve and purging the vapor phase gas in the fuel tank to the canister (501). A canister purge operation (502) in which the purge pipe is opened by the purge valve to purge the fuel component in the canister to the intake pipe, the vapor pipe is opened by the closed valve, and the purge pipe is opened by the purge valve. A purge operation (503) that opens and purges the gas phase gas in the fuel tank to the intake pipe by bypassing the canister, and an opening degree of the closed valve in at least one of the vapor operation and the purge operation. The control device (5) capable of executing each of the learning operations (504) is provided.
The control device is
An opening command unit (51) for transmitting an opening command amount (K1) for determining the opening of the closed valve to the actuator, and an opening command unit (51).
In the learning operation, when the opening command amount is gradually increased from zero, the valve opening start amount (K0) is based on the opening command amount when the pressure of the gas phase gas starts to decrease. With the valve opening start learning unit (52) to learn
The valve opening threshold (TH) for determining that the pressure of the gas phase gas has started to decrease is based on the pre-learning pressure (P0) which is the pressure of the gas phase gas before the time when the learning operation is started. It has a valve opening threshold value setting unit (53) and a valve opening threshold value setting unit (53).
When the closed valve is opened to perform the vapor operation or the purge operation, the opening command amount by the opening command unit is determined based on the valve opening start amount by the valve opening start learning unit, evaporation. Fuel processing equipment. The control device detects a pressure drop amount (ΔP) which is a value obtained by subtracting the pressure of the gas phase gas when the opening command amount is gradually increased from zero from the pre-learning pressure. It has a detection unit (54) and has a detection unit (54).
The valve opening start learning unit performs the learning operation when the internal combustion engine is stopped or when the operation is started, and the pressure decrease amount detected by the pressure decrease amount detection unit becomes equal to or greater than the valve opening threshold value. The evaporated fuel treatment apparatus according to claim 1, wherein it is determined that the pressure of the gas phase gas has started to decrease. The evaporated fuel processing apparatus according to claim 1 or 2, wherein in the valve opening threshold setting unit, the valve opening threshold is set to a larger value as the pre-learning pressure is higher. The control device is created by learning in advance the maximum value (Pmax) and the minimum value (Pmin) of the pressure pulsation waveform that changes depending on the level of the pre-learning pressure, and the relationship between the pre-learning pressure and the valve opening threshold value. In the threshold map, the valve opening threshold is set to a larger value as the pulsation amount, which is the difference between the maximum value and the minimum value, is larger.
The evaporated fuel processing apparatus according to any one of claims 1 to 3, wherein the valve opening threshold is set by reading the threshold map corresponding to the pre-learning pressure in the valve opening threshold setting unit. The valve opening threshold setting unit corrects the valve opening threshold set by reading the threshold map based on at least one of the environmental information inside and outside the fuel tank input to the control device. The evaporated fuel treatment apparatus according to claim 4. In the learning operation, the control device applies a plurality of different pre-learning pressures when the valve opening start learning unit learns a plurality of different valve opening start amounts corresponding to the plurality of different pre-learning pressures. The relationship learning unit (55) that learns the relationship between the corresponding gas phase gas pressure and the valve opening start amount and creates a relationship map (M1) between the valve opening start amount and the gas phase gas pressure. When,
At this time, the operating pressure (Pa), which is the pressure of the gas phase gas detected by the pressure sensor when the sealing valve is opened to perform the vapor operation or the purging operation, is collated with the relationship map. It has an opening correction unit (56) that reads the operation valve opening start amount, which is the valve opening start amount, and corrects the opening command amount by the opening command unit by the operation valve opening start amount. , The evaporated fuel treatment apparatus according to any one of claims 1 to 5.

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